Spark plug



Dec. 18, 1923. 11,478,292

V. F. MULKEY S PARK PLUG Filed June 9. 1921 Q 7 I Zlwucmfor V 1 Mal/31,7

i atented lies. l8,

VELIE F. MULKEY, F PLATTE CITY, MISSOURI.

SPARK PLUG.

Application filed June 9,

To all whom it may concern:

Be it known that l, Vonnm 1F. MULKEY, a citizen of the United States, residing at .llatte City, in the county of Platte and 6 State of Missouri, have invented certain new and useful improvements in a Spark Plug; and I do hereby declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled w in the art to which it appertains to make and use the same.

The invention relates to electric ignition for internal combustion engines and more particularly to a spark plug which provides 16 the spark gap essential to the operation thereof. y

The chiel ohject'in view is the provision of a spark plug which is practically self cleaning and prevents accumulation of oil or carbon and which maintains clean terminals and insures positive sparking when the current is properly supplied.

Other objects and advantages will be aparent and suggest themselves as the nature of the invention is understood.

While the drawing illustrates an embodiment of the invention it is to he understood that in adapting the same to meet different conditions and requirements, various changes in the term, proportion and minor details of construction may he resorted to without departing from the nature of the invention.

Referring to the accompanying drawing -forming a part of the specification,

Figure l is a side view of a spark plug illustrative of the invention,

Figure 2 is an elevation thereof partly in section, and

Figure 3 line of being omitted.

Corresponding and like parts are reierred to in the following description and designated in the several views of the drawing by like reference characters. a

The spark plug illustrated. is in general structure Oil ordinary formation and comprises a shell l, a nut or gland 2 and a core 3 of insulating material such as porcelain. The positive electrode 4 is mounted in the is a horizontal section on the co Figure l, the hall terminal 1921. Serial Ho. M6265.

core 3 in any preferred wav. The lower portion] of the shell 1 is externally screw threaded for attachment to the entrance in a manner well understood.

In accordance with the present invention the lower end of the shell 1 is closed and of rounded formation. An opening 5 is termed in the extremity of the closed end and is centrally disposed. ther openings 6 are formed in the sides of the rounded end of the shell and'are equally spaced apart. The openings 5' and 6 are practically of uniform size. -A metal ball 7 is located within the closed end of the shell 1 and is of such diameter as to prevent its escape through any one of the openings 5 or 6 and at the same time prevent its lodging in any one of said openings to prevent free movement thereof. The ball 7 constitutes the terminal of the negative electrode and the spark gap is formed between saidloall 7 and the terminal of the electrode 4;. The movement of the hall 7 prevents fouling of the plug and renders the same self cleaning as it prevents any accumulation of oil or carbon. The vibration of the engine, assisted materially by the jolt and jar of the vehicle, and the disturbing action of compression and explosion of the fuel insure movement of the ball terminal 7, whereby any oil or carbon tending to accumulate is disloged and the terminals kept clean thereby insuring positive sparking when the current is properly supplied to the plug in the operation of the engine.

llaving thus described the invention, what I claim is A. spark plug having its shell continued below the lower end of its positive electrode and rounded and closed, a relatively large hall loose in said closed end and forming the ground terminal of the spark plug, said closed end having a central opening in its lower wall and having equally spaced openings in its side wall, all of said openings being round and having a continued bore and. being of less diameter than the diameter of the ball, the openings in the side wall having their upper edges substantially in the plane of the lower end of the positive 1 electrode and having their central axis In testimony whereof I afiix my signature above the central axis of the ball whenthe in presence of two witnesses. ball is in normal position, whereby the ball is spaced from the positive electrode and VOLLEE MULKEY 6 the openings in the side wall are in align- WVitnesses:

ment with the :point where the'spark will J. C. Hermon,

occur. DICK OL1DHAM. 

